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View Full Version : Air Bag Setting and Tire pressures


Martin0660
08-26-2006, 09:19 PM
I'm chasing this new set-up in the Capri a little, and looking for some baseline settings from anyone. My stuff is way different than most, so there might not be a lot of cross over, but lets hope ;) I leave at 5200 rpm off the two step at 10 pis boost, so it hits pretty hard on the sidestep. 60' timers have all been in the 1.7 or higher range on all tubular arms, and such.

I have Hoosier Quick time Pro's, 26/9.50/16. I think I've mostly been chasin "new" tires rto this point as they seem to have gotten better, but I had been blowing them away. Right now, I'm running them at 10 psi in them, but they might be too low.

Here is the attitude of the car stagged.......

http://community.webshots.com/photo/552689740/2238015230066453426gICBtL

On that pass, the car got REAL loose in third gear. I didnt see any pictures until I got home tonight, but this is what wifey managed to catch....

http://community.webshots.com/photo/552689740/2295717290066453426ykoGQE#

:eek: Now, it sure looks to me like the left rear was way too low, causing the loose situation. I am positive both were at 10psi going out, and they were at 11.5 after the pass. Now, after this pass, I put the airbag in the right rear to 5 psi (it was at zero). Wifey didnt catch it early in the run, but it did feel a lot better (but also in the right lane). A downtrack picture.......

http://community.webshots.com/photo/552689740/2527006940066453426sOhxzg#

It sure looks better in that picture, but its also way further down track. so my questions, what does everyone think for pressure in the QTP's and where is a good starting point for the air bag?

I will keep tuning on these, but it just seems I've started a bit out of the center here, and need to get "back". The problem as you all know, is TnT passes are so darned limited, I just havent got enough to find a baseline. I think the tires are finally settled in now, and could probably go higher in pressure now.

Any input is appreciated.

Bob Myers
DING
08-28-2006, 04:13 PM
I have ran a much as 30 psi in an air bag. 1.50 sixties. I typically ran 20 psi in the bag. Air pressure in the tires varies, slicks you can run a little less psi but with a drag radial they like a little more air in them. As all cars are different it takes a little playing to get where you want to be.

Good Luck
somethingclever
08-28-2006, 04:18 PM
i'm not sure about air bag pressure....but i remember your car stepping to the right HARD on launch and shifts. Something is amiss.
Martin0660
08-28-2006, 04:44 PM
I have ran a much as 30 psi in an air bag. 1.50 sixties. I typically ran 20 psi in the bag. Air pressure in the tires varies, slicks you can run a little less psi but with a drag radial they like a little more air in them. As all cars are different it takes a little playing to get where you want to be.

Good Luck

Thanks, I am working way lower than that in the bag. Going from nothing to 5psi helped straighten it out some ;) I will try starting it up at 15 psi or so, and go up if needed. I'm running biased Hoosier Quick Time Pro's so no radials here.


i'm not sure about air bag pressure....but i remember your car stepping to the right HARD on launch and shifts. Something is amiss.

Yeah, it scared me a bit :eek: , my first pass Saturday was especially scarry. I've been over every nut and bolt on the rear, the rear is square to the wheel base, the crossmember, and everything I can measure too. I cant find anything binding, etc. I usually work through this stuff myself, but this sucker makes my a'hole pucker right now. Funny thing is, its straight as an arrow up top, no slick walk or anything. Its just real sqiurly UNDER power, at the top of the gears its okay too.

Oh well, I will get bac kat it on Wednesday and see what we can find (and hope its not the guardrail).

Bob Myers
DING
08-29-2006, 08:04 AM
Put more air in the bag and you'll be fine. Also have you sent your pinion angle?
Sonic03snake
08-31-2006, 01:32 PM
The looseness you are experiencing may also be due to you running bias tires in the rear and radials up front. I seen cars get real out of shape with that combo. I ran my hoosier QTP's @ 11 - 12 psi and had good luck there.:cool:
Martin0660
08-31-2006, 05:35 PM
The looseness you are experiencing may also be due to you running bias tires in the rear and radials up front. I seen cars get real out of shape with that combo. :

I've always heard those stories but never experienced it. This very well could be, but I would of thought it would have been worse at higher speed? I got to settle down enough its not scatrring me anymore, so i'm going to borrow a set of skinnes and give it a try, that should confirm this ;)


I ran my hoosier QTP's @ 11 - 12 psi and had good luck there.:cool:

Tha nks a bunch. They reall only seemed to like to be 10 or below, but now that they have "come around" they are pretty decent at 12, and were okay at 14. I'm zoning in on it.

Thanks Lou
Bob Myers
Sonic03snake
08-31-2006, 06:11 PM
No problem Bob.:cool:
I've always heard those stories but never experienced it. This very well could be, but I would of thought it would have been worse at higher speed? I got to settle down enough its not scatrring me anymore, so i'm going to borrow a set of skinnes and give it a try, that should confirm this ;)



Tha nks a bunch. They reall only seemed to like to be 10 or below, but now that they have "come around" they are pretty decent at 12, and were okay at 14. I'm zoning in on it.

Thanks Lou
Bob Myers
Mater
08-31-2006, 08:56 PM
The looseness you are experiencing may also be due to you running bias tires in the rear and radials up front. I seen cars get real out of shape with that combo. I ran my hoosier QTP's @ 11 - 12 psi and had good luck there.:cool:

i agree!